【机械类文献翻译】数控加工技术概述

原文：The digital control process technology i s summarized1.digital control programming reaches such developmentThe digital control programming is the segment that be able to obviously bring into play the beneficial result in at the moment CAD/CAPP/CAM's system the most most,such is living to achieve to design the process automation and raise process accuracy and processes the quality and cuts down the product development cycle and so on the respect is brining into play the significant action.Being living possess the greats quantity applications such as aviation industry and auto industry and so on territorys.Since giving birth to the intense demand of practice, wide-ranging research has wholly been carried on to the digital control programming technique in the home and abroad,and acquires the plentiful and substantial fruit.The next reaches such to the digital control programming and develops to act as some to introduce.1.1basic concept of digital control programmingThe digital control programming is through the spare parts drawings up the full process that obtains the digital control processing program.Its main mission is that the sword spot(Cutterlocationpoint abbreviate CL's spot)in the sword is processed away in the calculation.The point of intersection that sword the spot was oridinarily get to the cutting tool axial line against the cutting tool face still will be give out the sword shaft vector in much processs1.2digital control programming technique development surveyMIT designed one kind of special language that is used in the inflexible spare parts digital control processing program establishments to the program problem in order to resolve in the digital control process,andis called APT(AutomaticallyProgrammedTool)in the50's.Well-developed editions such as after APT time and again develops,takeed shape such as APTII and APTIII(the stereoscopic cutting action is employd)and APT(the algorithm improves,add much coordinates surface processes the programming meritorous service capacity)and APTAC(Advancedcontouring)(add cuts the database administration system)and APT/SS(SculpturedSurface)(add engraves the camber processes the programming meritorous service capacity)and so on.Adoping APT language drawing up digital control order to have easy the refineing of order,and gos away the strongs point such as sword control is agile and so on,and causes the digital control process the programming,and moves upward up yet possess much not suitable points to geometry element.APT through"assemble language"grade to the machine tool order:Adoping language definition spare parts geometry form shape,and is difficult to depict complex geometry form shape,and lack audio-visual quality of geometry;The certification measure that the figure audio-visual that is short of to spare parts form shape and the cutting tool movement locus displays and the cutting tool locus;Being difficult to effectively join with CAD's data bank and CAPP's system;Not to act as easily up the high automation,the integrationizationIn view of the APT's language defect,in1978,France attained the system that the large rope airplane corporation starts development gathers assemble three dimensions design,analysis and NC's process integration, and is called in the interest of CATIA.Having ariseed alikely the systems such as EUCLID and NPU/GNCP and so on soon afterwards very quickly,the geometry moldswholly valid settlements of these systems and the spare parts geometry form shape display is designed mutually and mends generates the cutting tool locus,and the problems such as the imitation to go away the sword process displays and certification and so on promoteed CAD and CAM developing to the integration orientation.The approximately idea that system(CIMS)and parallel project(CE)was manufacture in the calculating machine integration take shape up the80's gradually on the base that the CAD/CAM's integration being living is approximately attend school.At the moment,and the necessaries that CE developed in order to adapt to CIMS,the digital control programming system to integrationization and intelligentization the development.Being living the integration respect,with the development accords with the STEP(StandardfortheExchangeofProductModelData)criterion parameterization feature moldmaking and systematically gives priority to,having carried on the highly effective work of greats quantity at the moment is the home and abroad development heatpointBeing living the intelligentization respect,the work has start only a short while ago,and still awaits that we leave hard2、NCs'cutting tool locus generates the method study developing actualityDigital control programming core work is generateing the cutting tool locus,afterwards by such scattered one-tenth sword spot,places that the handle comes into being the digital control processing program afterwards viaing.The next cutting tool locus comes into being the means and actes as some and introduce2.1baseding on a little and string,surface and part of the body NC's sword track formation meansCAD's technique moves through the two dimension mapping,andudergo the three dimensions wires frame and camber and the solid modelling generation,now the parameterization feature reacing is always moldded.Is living two dimension mapping together with three dimensions wires frame phase,in case the opening processes,the rough sketch is processed the digital control process is main with spot and string act as drive target,the plane area process and so on.This kind of level that personnel staff was requireed manipulating in the process is taller,complex mutually.Being living camber and the solid modelling generation,entity process had ariseed to based on.The entity process target is an entity(oridinarily blendes for CSG and BREP express),its(moreover,intersects,falls short of to operate) but get yield through some fundamental parts of the body habitually after the set operation.The entity is processed not merely usable rough machining and semi precision work to the spare parts,and the great area cuts Yu Liang,and the effectiveness is processed in the raise,but also usable research together with development to digital control baseding on the feature programming system,is the feature process baseEntity process oridinarily possess entity rough sketch process and the entity area and processes two kinds.The entity process realization means slices law(SLICE)in the interest of the straturm,in immediate future slices by the process entity in the way of one series of level,afterwards to obtains the intersection comes into being the isometry string dos worthwhile the sword the going away locus.The original slave system needs the angle depart,the digital control process that the ACIS's geometry moldmaking being living achieved thiskind to based on a little on the terrace and the string and surface and entity Feature NC's sword track formation means2.2baseding onThe parameterization feature molds to possess the specified development particular period,yet baseds on that feature cutting tool locus formation means research starts only a short while ago.The feature processes to cause digital control programming personnel staff to be out to let drop the step geometry message to those (in case:Spot,string,surface and entity)manipulate,but transforing to carry on the digital control programming in the interest of directly to accords with the feature that engineers and technicians are used to,and liftd the programming effectiveness enormouslyW.R.Mail and A.J.Mcleod are living in their research to give out one to based on feature NC's code generating sub system,and this systematic work rule is:Spare parts every one process wholly may be regarded as to adjust to make up the total that the spare parts form shape feature group processed.In immediate future the queen completees spare parts process is not processed that to the feature adjusting entirely form the shape in that way either form shape feature component.But each form shape feature either form shape feature series NC's code may generate voluntarily.The system opened up at the moment merely is applicable to2.5D's spare parts processThe LeeandChang opened up one kind of raised liberal camber feature cutting tool locus of means autogeneration in the way of fictitious border system.This systematic work rule is:Being living to inlay inner place the raised liberal camber into one the minimal long and square,so raised liberal camber feature is transformd into the hollow feature.Minimal the long and square incorporation against the end product pattern constituteed to be called one kind of indirect produce pattern on the fictitious pattern.That the cutting tool locus formation means separates into completees three paces:(1)and the cutting action polyhedron feature;(2)and cuts the liberal camber feature;(3)and the cutting action intersects the featureJongYunJung researcies baseds on the non-cutting action cutting tool locus formation problem of feature.The article process baseding on the feature locus separates into rough sketch process and processes two types with the inside area,and the definition this two types of process cutting action orientations,attains the aim that the entirety optimizes the cutting tool locus by means of decreasing the cutting action cutting tool locus.Type who talked about these fundamental features gos away sword way and cutting tool selection and process order and so on to main being aimed at of article some kinds of fundamental features(hollow inner place Kong and step,trough),and averting repeatedly going away the sword by means of IP(InterProgramming)technique,with the non-cutting action cutting tool locus of optimization.Besides JongYunJong still is living,and his doctor in1991 researcied tabrication feature extraction and baseds on feature cutting tool and the cutting tool way in the dissertationThe feature process base is an entity process,and surely of course also may think the entity process being more high-quality.Yet feature process distinct entity process,and entity process possess it oneself the limitations.Feature process chiefly possess below difference against entity process:Through approximately attends school says that the feature is the meritorous service capacity key element to make up the spare parts,and the operation that accords with engineers and technicians is used to,by engineers and technicians are know intimately;The entity is the geometry target on low straturm,and is a geometric object that obtains after a series of Booleans calculation,and does not have whatever meritorous service capacity semantic information;It frequently is adjusting the once only process of entire spare parts (entity)that the entity is processed.Yet in reality the spare parts is not very much probably merely once processed through in the way of the sword,frequently will go through a series of workmans of rough machining and semi precision work and precision work and so on stage,the place of spare parts difference oridinarily will be employd the difference cutting tool and process;Now and then not only the spare parts will be employd up turning, but also employ up mill.Hence entity process is chiefly used spare parts rough machining and semi precision work.But but the feature on processing through essentially resolved the above-mentioned issue;Feature process havees even more intellect.May regulate some kinds of settled admittedly process meanss as to the specially designated feature,particularly those have been living,and STEP's criterion the person who regulates the feature still more is such in this way.In case we wholly draw up the specially designated process means to all standards feature,it is you can imagine that spare parts that in thatway sufficiently succeed through the standard feature to those are processed such convenient quality.In case CAPP systematically be able to supply the relevant technology feature,NCP's system may decrease inputing mutually,and havees even more intellect enormously in that way.But these entity process can not achievedFeature process is favour of achieving through comprehensive integration of CAD,CAPP,NCP and CNC's system,and achieves the two-way going from place to place of message,in the interest of CIMS and even parallel project(CE)are settleed the well base;It be helpless that but the entity is processed to theseNC's sword track formation means2.3being on active service in several main CAD/CAM's systems is analysedActive duty CAM constitutes reaching the main meritorous service capacityThat at the moment comparatively more mature CAM's system is main with two kinds of shapes achieves CAD/CAM's system integration: Integration CAD/CAM's system(in case:UGII,Euclid and Pro/ENGINEERs and so on)and independent relatively CAM's system (in case:Mastercam and Surfcams and so on).Unitary less than the former data format is directly gaind the produce geometric model through CAD's system,but the latter is main gains the produce geometric model by means of the neutral papers through else CAD's systems.However,no matter is what the CAM's system growed the shape,wholly consising of five modules,in immediate future mutually technology parameter input module and cutting tool locus formation module and cutting tool locus compiler module and three dimensions process that dynamic imitation module and afterwards places the processing module.Next merely some famous CAD/CAM's system NC's process meanss are holied discussions.UGII's process means is analysedOridinarily think that UGII is the best in trade circle,and havees representativeness digital control software most.That such havees the distinguishing feature most is the cutting tool locus formation means that such meritorous service capacity is powerful.Consists of turning,milling and string cuts and so on the consummate process means.In it milling chiefly possess the below meritorous service capacity:And PointtoPoint:Completeing the different openings processesAnd PanarMill:Plane is milled.Consising of that the one-way walkes surely,the two-way row are slice,and the hoop is slice along with rough sketch process to await And FixedContour:Admittedly much projectionss are areed processed stably.Dominateeing on being living on the single camber either much camber the removing of cutting tool in the way of the projection means, and that the control cutting tool is removed may be the cutting tool locus that has generateed,a series of either suite stringAnd VariableContour:Variable projection is processedAnd Parameterline:Await that the parameter string is processed.The successive process of single camber either much camber may be adjustAnd ZigZagSurface:Cutting out processAnd RoughtoDepth:Rough machining.The depth is reachd assigning in the rough machining by Mao PiAnd CavityMill:The many stages depth mould cavity processes.Rough machining that particularly is applicable to the male contact with the hollow standardAnd SequentialSurface:The camber occuies simultaneously the workman.In accordance the spare parts and guides that and the thinking of check adjust the removing suppling the largesttest degree control of cutting toolEDSUnigraphics still consists of greats quantity else the respects meritorous service capacitys,and did not enumerate one by one here STRATA's process means is analysedSTRATA is a digital control programming system development environment,and it is establishing ACIS's geometry model building terrace onIt supplys two kinds of programming development environments in the interest of consumer,in immediate future NC's command language interface and the NC's operation C++storehouse.It may back three to mill,and turning and string cut NC and process,and may back wire frame,camber and the entity geometry model building.Such NC's cutting tool locus formation means is baseding on the physical model. STRATA is baseded on,and what supplys the process means in entity NC's cutting tool locus formation type storehouse consists of:ProfileToolpath:Rough sketch processAreaClearToolpath:The area on plane processesSolidProfileToolpath:The entity rough sketch is processedSolidAreaClearToolpath:The area on entity plane processesSolidFaceToolPath:The entity face processesSolidSliceToolPath:The entity severs process on planeLanguagebasedToolpath:Baseding on,language cutting tool locus generatesElse CAD/CAM software,in case Euclid the person who awaits the NC's meritorous service capacity is each has his strong point,yet suchfundamental substance is almost alike,the not natural difference.2.4main problem of systematic sword track formation means of active duty CAMIn accordance tradition CAD/CAM's system and CNC's system work means,CAM's system is with directly either the indirect means gains the produce geometry data model through CAD's system(by means of neutral papers).CAM's system is with spot,string,surface in the three dimensions geometrics model and either the entity is the drive target,the cutting tool locus is processed in the formation,and afterwards the shape with the cutting tool locating file viaes the handle is placed,with the NC's code shape supplys to CNC's machine tool,the some respects problems under being living in entire CAD/CAM and the CNC's system operation process to be:CAM systematically can only gain produce low tier of geometry message through CAD's system,and can not seize voluntarily meritorous service capacity and the semantic information of produce geometry shape information and produce higher level.Hence manufacturing engineering master that entire CAM's process have to be living is very experience haves a hand in secondly,and completees mutually by means of the figure.In case:Manufacturing engineering master.The entire system automation degree is leted dropBeing living in the CAM's system generation cutting tool locus, equal also merely embodying low straturm geometry message(right line and arc geometry locating information),along with the a little process control information(as moving forward)to rate,main shaft rotation speed and trading sword and so on.Hence,can not obtain the process technology parameter that haves something to do with against generateing the cutting tool locus yetThe produce data between CAM's system every module are not unitied,and the independence is opposite to each other to every module.For instance the cutting tool locating file is merely keep the minutes the cutting tool locus and is not keep the minutes the relevant process technology parameter,the dynamic imitation of three dimensions merely keeps the minutes that the cutting tool locus interference against runs into,but keep the minutes interference and process target and correlation process technology parameter that runs into happen against suchThe CAM systematically is an independence system.Not thering is the unitary produce data model between CAD's system together with the CAM's system,even if being the integrated CAD/CAM's system of integration in,one-way and unity is enjoyed also being only to message in all.CAM systematically can not sufficiently comprehend and complete message utilizing CAD's system to have something to do with the produce,feature message that especially haves something to do with against process,equal CAD's system can not gain the process data message that CAM systematically come into being yet. This is give parallel project implementation to bring the hardship3、digitals control techniques of simulation3.1calculating machine imitation approximately idea and applicationThe angle through the project is see,and the imitation is the system by means of the test to the system model leave to research in the existing either design.Analysing the complex dynamic target,the imitation is one kind of valid means,may decrease the hazard,cuts down design and manufactures cycle,and practise thrift the investment.Calculating machine imitation is draing support from the calculatingmachine,and utilizes the system model to adjust actually systematically testing the process which researcied.It is swiftly developed in the wake of the calculating machine technique development,and is living in the imitation to passess the more and more significant position.Three foundation maneuveies between the key element that the calculating machine imitation process may be notify by means of the picture1are depictd:The model building maneuver is by means of viewing either examination to the actual system,and is living to over look the less important element to reach on the base that examine the variable,and the means in the way of physics either mathematics is depictd,thereby obtains the similar pattern of actual system simplification.The meritorous service with the actual system of the pattern here be able to together with between the parameter ought to have similarity and homologous qualityThe imitation pattern is the mathematical model to the system (simplifying the pattern)carries on the specified algorithm handle,and causes such become the appropriate shape(in case turns into iterative operation pattern by the numerical integration)afterwards,yet becomes" computation module computational mode"that be able to be receiveed by the calculating machine.The imitation pattern is two simplification patterns to the actual systemThe imitation test is shall system imitation pattern be living the process rund in the calculating machine.The imitation is researching actual system one kind of technique by means of the test,may clarify systematically immanent structure variable and the ambient condition effect by means of the technique of simulationCalculating machine technique of simulation main expressing of development tendency be living two respects:Application territory enlargement and imitation calculating machine intelligentization.The calculating machine technique of simulation not merely is living tradition project technique territory(respects such as aviation,spaceflight and chemical industry and so on)subsequent development,but also broadens up community economy and living beings and so on much non-project territorys,moreover,technique such as parallel processing, artificial intelligence,knowledge base and expert system and so on the development is affecing the imitation calculating machine development Digital control process imitation utilizes the calculating machine imitation practice process,being the forceful means to verify digital control processing program dependability and the calculation cutting action process,in order to decrease work attempies surely,and lifts production efficiency3.2digital control technique of simulation research present situationThe APT process spare parts are completeed near the digital control order program control.In the interest of right quality to guarrantee the digital control order, guard against in process to intervene happenning,and is living in the actual manufacture,and constantly adopts attempting the anxious means to examine with what runs into.Yet this kind of means requiring a lot of labor expense is anticipateed,the cost expansively causes the manufacturing cost move upward,addd produce process time and production cycle.Adoping once more the locus to display the law afterwards,in immediate future in order to mark needle either pencil or writing brush replace the cutting tool,with colouring plank either paper replaces the work imitation cutting tool movement locus two dimension figure(alsomay display the two dimension semi process locus),possess the considerably great limitations.Three dimension and the many-dimensionss as to the work are processed,the cutting action locus that the inspection that the stuff that also possess use easily to cut replaces the work(in case,paraffin wax, lumber,midified resin and plastic material and so on)comes is processed.Yet APT and the process field is very important occupied in the attempt.For this reason,people are living always to research replace gradually attempting the anxious calculating machine emulation mode, and is living to attempt to slice that the respects such as environment modeling and imitation calculation and graphic display and so on acquire the significant progress,and develops to raise pattern accurateness and imitation calculation real timeization and improvement real feeling of graphic display and so on orientations at the momentThrough attempies the pattern distinguishing feature sliceeing the environment seeing,NC's cutting action process imitation branch geometry imitation and mechanics imitation at the moment two respects.Geometry imitation is not consider that cutting action parameter and cutting force reach else the physics elements effects,the imitation cutting tool work geometric object movement,and with right quality of certification NC's order.The problem such as it may decrease either remove as a result of the machine tool injury that the program error causes and clamping apparatus damage either the cutting tool rolls over to snap and the spare parts are reported something as worthless and so on;May decrease moreover through the product design up time manufacturing,and cut down the manufacturing cost.Cutting action process mechanics imitation pertains to the physics imitation category,and its dynamic mechanics property by means of the imitation cutting action process is forecast that the cutting tool breakage and cutting tool vibration and control cuts the parameter,thereby attains to optimize the cutting action process aimThe geometry technique of simulation development is in the wake of geometry model building technique development but development,and consists of that quality graphic display and the ration is intervened verifying two respects.At the moment the means in common use possess the immediate solid modelling law,and the means of figure image space baseding on is requestted the intersection law with the scattered vector3.3immediate solid modelling lawThis kind of enveloping solid that the means is the work part of the body against the cutting tool movement takes shape is underway that the entity Boolean falls short of operating,and the work part of the body three dimensions patterns are continuously replaceed in the wake of the cutting action processSungurtekin and Velcker opened up a miller simulation system.The three dimensions patterns that ought to systematically adopt CSG's law to keep the minutes Mao Pi utilize some fundamental primitives like cuboid,the cylindrical body and taper part of the body, and the set operation,particularly operating,the area by Mao Pi and a series of cutting tool scannings is keep the minutes,afterwards usies the set difference and operates through Mao Pizhong's order take-offing the scanning area.Traverse when the so-called area by has sweep is cutting the cutting tool to move along some locuss area.Per length of Mao Pixing's shape that NC's code afterwardsdisplay the alternation being living scanningKawashima the person who awaits the joint tree law is expressed Mao Pi and the cutting action area in the way of the joint tree(Graftree), in immediate future and Man Liang's kind connection except for empties the border connection is also as the leaf nodes of eight forks trees (Octtree).The border connection embodys the half-space,and the CSG's operation that the connection substance utilized these half-spaces on to express.The half-space figure that the joint tree subdivided step permitted through the border connection is resolved.The cutting action imitation gradually utilizes Mao Pi and cutting action area to fall short of to operate achieving.The depth buffer algorithm was adoptd in the display of Mao Pi,by Mao Pi divides achieves the looking upon of Mao Pi in the interest of the polygonIn the way of the real time baseding on solid modelling means successive renewal of realization Mao Pi may looking upon,very much elder when cosing,the observation means is propose then some are baseded on3.4means of figure image space baseding onThis kind of blanking algorithm that the means was employd figure image space is achieved the entity Boolean calculation.The VanHook adopts scattered law of the image space dynamic figure imitation achieved process.He employs analogous figure blanking Zbuffer's idea,scattered along the view orientation by Mao Pi and cutting tool,is living every one Mao Pi and the cutting tool expresss being called Dexel's composition in the interest of the cuboid along Z's shaft on the screen pixels.。